It is known that electronic apparatuses have the drawback of having an energy source which discharges over time. Consequently, there exist methods of managing the energy of the electronic apparatus so that the energy source has the longest possible autonomy. For this purpose, various energy managing methods have been invented and generally speaking, after the actuation of a trigger element, these energy saving methods consist in stopping the highest electricity consuming function such as the LCD display or the motion of the hands.
For example, management methods are known wherein the trigger element is the actual user. The user controls the start of the energy saving mode himself. To achieve this, he operates push buttons or other control means of the electronic apparatus to activate the energy saving mode.
One drawback of this method is that the user is not methodical. Indeed, the user will not always start the energy saving mode when it is required. He will activate this mode when he leaves for a few days but not necessarily every night. Optimum energy saving is therefore not achieved.
Methods are also known wherein the activating element is based on the level of a physical magnitude. For example, activation may occur when the ambient light falls below a certain threshold indicating that the electronic apparatus is in darkness. Activation may occur when the electronic apparatus detects that it is no longer being worn. This is achieved by the use of an accelerometer which is sensitive to any motion of the electronic apparatus.
One drawback of these methods is that the energy saving mode may be activated spontaneously when it is not required or desired. Indeed, if the electronic apparatus spends extended time in a tunnel or inside a sleeve, or if the user wearing the apparatus falls asleep so that said apparatus detects a lack of motion, the energy saving mode may be activated unnecessarily. The functions are then deactivated and the user no longer has immediate access to data and has to reactivate the normal mode to achieve access. This therefore becomes a source of irritation for the user.